Train-control system



Oct. 10, 1933. L, oNEg 1,929,980

TRAIN CONTROL SYSTEM Filed Feb. 3, 1927 4 Sheets-Sheet 1 -I 5 We 52 14' Con W Reaulfanf coilw w Lesier L.Jone5 NORMAL RUNNING TRIPPING OVER RESET OVER INERT TRACK ELEMENT TUNED TRACK ELEMENT Oct. 10, 1933. L JQNES 1,929,980

TRAIN CONTROL SYSTEM Filed Feb. 5, 1927 4 Sheets-Sheet 2 NORMAL TR'PPING no TRIFOVER RESET OVER RUNNING OVER 'INERT TRACK RON RAIL TUNED TRACK ELEMENT ELEMENT 9] 9 90 Tag I CollW A B Q D ResuHqnT=32 R H 1=8 Re5u|farff= Rcsul1urlt=l 17s |80 I E BoHon; 3 {muse amn- PHASE :mrr CmlW W =6 APPROX- =E|APPROX.

SI so dumb limb 4E5; M INVENTOR x h fl ATTdNEYS Oct. 10, 1933.

L. L. JONES TRAIN CONTROL SYSTEM 4 Sheets-Sheet 3 1 Filed Feb. 5, 1927 Leskr L.Jo.nes 2 BY ATT RNEYS Oct. 10, 1 933.

L. L. JONES TRAIN CONTROL SYSTEM Filed Feb. 3, 1927 4 Sheets-Sheet 4 INVENTOR Lesrer L. Jones BY ATT RNEYS Patented Oct. 10, 1933 TRAIN-CONTROL SYSTEM Lester L. Jones, Oradell, N. J.

Application February 3,

57 Claims.

' application of Theodore Bodde, Ser. No. 145,192,

filed Oct. 30, 1926.

In train control systems of this type, there are provided vehicle carried and roadside inductors which cooperate for actuating vehicle carried apparatus in response to roadside conditions, the roadside inductor embodying under one roadside condition an inert magnetic mass which influences the vehicle carried inductor to produce a given, such as a tripping operation of the vehicle carried apparatus, and embodying under another roadside condition a closed circuit devoid of an energy source and operative to influence the vehicle carried inductor to produce another operation such as a resetting operation of the vehicle carried apparatus. The vehicle carried inductor of this train control system comprises inductively coupled coils affective for normally maintaining the energization of the vehicle carried apparatus and operative when the same is moved over the roadside inductor With the latter active as an inert magnetic mass for effectively deenergizing the vehicle carried apparatus to produce a tripping operation thereof, the said coupled coils being further operative when moved over the roadside gization or resetting of the vehicle carried apparatus.

The prime object of my present invention relates to the provision of constructional and operational improvements in the vehicle carried and roadside inductors employed in this type of system whereby a number of distinct and Well defined operations, such as the normal, tripping and resetting operations, are obtained in the vehicle carried apparatus and correspondingly distinct influences are produced by the roadside inductor on the vehicle carried inductor for effecting either the tripping or resetting operation or both.

In controlling the vehicle carried apparatus by means of a single vehicle carried inductor coopcrating with a single roadside inductor, and in producing in the vehicle carried inductor the normal, tripping and resetting influences or operations, it is essential or highly desirable to make provision for a fairly large range of energy Variainductor in closed circuit for producing a reener- 1927. Serial No. 165,612

tion for each of such operations or influences and to provide for a substantial range or margin of safety between the energy zones allotted to each of such operations or influences. -The problem involved in accomplishing these results becomes manifest when it is appreciated that the energy generated or developed for producing the normal or tripping or resetting influences may vary within substantial limits due to a number of varying factors in the system, and that the zone or range of energy variation intended for producing one influence should desirably be separated with a substantial margin from the zone allotted to another influence so as to prevent any possible overlapping of zones of operations. This may be seen more clearly when the mattert is viewed in the light of the magnitudes of current necessary for operating a vehicle carried translating device or relay controlled by the cooperative vehicle carried and roadside inductors. For each of the operations, that is, the normal, tripping and resetting operations, provision should be made for a variation of current between maximum and minimum limits, and the zones defined by these limits should be separated by large margins of safety. It will therefore be seen that for producing all of the operations a substantial or wide range of energy variation must be provided for; and a principal object of my present invention centers about the provision of improved cooperating vehicle carried and roadside inductors operable for rendering possible the production of such a large band of energy variation for the different operations to be effected.

To accomplish the foregoing generalized re sults, it is a further and more specific object of my present invention to so design and construct the inductive apparatus of the system as to permit the definite and separate control of the phases and the magnitudes of fiux variations produced in the operation of the inductive apparatus. By so separately as well as conjointly controlling the phases and magnitudes of the flux variations produced in the operation of the system, I am enabled to produce predetermined operations of the vehicle carried inductor-within Well-defined limits, and more specifically, I render possible the obtaining first, of a normal current of substantial magnitude, second, the obtaining of a tripping current of zero value, and third, the obtaining of a reset current of a magnitude substantially high ductors, I may cause the vehicle carried inductor to discriminate in its operation of the controlling circuits on the vehicle between a magnetic mass such as the inert inductor and other magnetic masses such as rails, switches, crossings and the like. The system may be furthermore so designed that the movement of the vehicle inductor over rails and the like will have no efiect upon the normal operation of the system; and the provision of an inductive apparatus for accomplishing these improved results is a further prime desideratum of my present invention.

Other objects of my present invention include the provision of a train control system in which the foregoing results may be achieved by the use of a single vehicle carried inductor and a single roadside inductor. A still further object of the invention relates to the provision of inductive apparatus in which the normal, tripping and resetting operations may all be eiiected without employing roadside energy, the roadside inductor being either inert under danger conditions or embodying a circuit devoid of an energy source under clear roadside conditions.

To the accomplishment of the foregoing and such other objects as will hereinafter appear, my invention consists in the elements and their relation one to the other, as hereinafter more particularly described and sought to be defined in the claims, reference being had to the accompanying drawings which show the preferred embodiment of my invention, and in which:

Fig. 1 is a wiring diagrammatic view of a train control system embodying the improved vehicle carried and roadside inductive apparatus of my invention, 1

Fig. 2 is a circuit diagrammatic view of the vehicle carried and roadside inductor mechanism and showing vectorially the characteristic operations thereof,

Fig. 3 is a view similar to Fig. 2 showing a modified form of vehicle carried inductor mechanism,

Figs. 4 to 8 are views showing the constructional features of the vehicle carried and road side inductors of my present invention, of which Fig. 4 is a vertical elevational view thereof with parts shown in section,

Fig. 5 is a view of the vehicle carried inductor taken in cross-section on the line 55, Fig. 4,

Fig. 6 is a cross-sectional view of the same taken on the line 6-6, Fig. 4,

- Fig. 7 is a cross-sectional View of the roadside inductor taken on the line 7'?, Fig. 4, while Fig. 8 is a cross-sectional view of the same taken on the line 38, Fig. 4.

The underlying principles of my invention and the constructional and characteristic operations of the vehicle carried and roadside inductors may first be described in connection with Fig. 2 of the drawings which shows diagrammatically the vehicle carried and roadside inductive system and vectorially the characteristic operations thereof under various roadside and vehicle conditions.

The vehicle carried-inductor mechanism generally designated as VI comprises a primary inductor P having two magnetic or flux paths which may be described as an external flux path represented by the arrowed line EFP and a shunt or local flux path represented by the arrowed line SFP and a secondary inductor S having a plurality of windings W, W and W arranged in both of the flux paths of the primary inductor. The said primary inductor comprises a coil energized by a primary circuit p from an alternating current source A. 0., and the said secondary inductor S is connected to operate an electrically operated device or relay R arranged in a secondary circuit .9, the said secondary circuit being preferably tuned or made resonant by means of a condenser c.

The roadside inductor mechanism which cooperates with the vehicle carried inductor mechanism in the movement of the vehicle over the roadside comprises an inductor generally desig nated as RI embodying a magnetic or metallic mass M forming the core or winding W, which coil or winding is arranged in a circuit t tuned or made resonant by means of a condenser c, which tuned circuit is closed or opened by means of a controlling switch SW therein. When the vehicle inductor VI cooperates with as by moving over the roadside inductor RI, the roadside inductor is included or embraced in the external flux path EFP or" the vehicle carried inductor, as shown in Fig. 2 of the drawings.

The primary inductor coil P and the two secondary windings W and W are all wound on the same core 10 having pole pieces 10 and 10 which cooperate with the pole pieces 11 and 11 of the roadside inductor core M; and the secondary winding W is wound on a separate core 12, the poles 12 and 12 of which are arranged at the poles of the primary coil P and between the primary coil and the secondary coils W and W The external magnetic circuit or flux path EFP may be said to include the main pole pieces 10 and 10 and the inert track or roadside core or element M and the shunt magnetic circuit or flux path SFP may be said to include the shunt core 12, the main core 10 over which the primary P is wound being common to both paths.

In the apparatus thus far described, it is desired to produce three distinct controlling operations of the electrically operated device or relay R or of the secondary circuit 8, such operations being a normal energizing operation of the relay R, as when the vehicle carried inductor V1 is moving between controlling stations; a tripping or deenergizing operation of the relay R, as when the vehicle inductor VI is over an open circuited or inert roadside inductor M; and a resetting or reenergizing operation of the relay R, as when the vehicle carried inductor is over the roadside inductor with the winding W in a closed tuned circuit. To produce these three distinct operations efiiciently, particularly when a single control element or relay R is used to receive and translate these operations, the normal energizing current, the tripping out current and the reenergizing current for the secondary circuit s should differ widely'in value or magnitude; and in order to make provision for the normal variations of the remaining parts of the system, such as those due to change in speed of the alternating current source A. C., variation in air gap between the vehicle and roadside inductors, all of which affect the inductive influences which produce the resulting energizing current in the secondary circuit s, it is manifest that provision must be accordingly made for variations between maximum and minimum limits of current for producing each of the distinct operations, thus producing a zone or range of current variation for each of said operations. Furthermore, in order to inhibit any possibility of overlapping of instructed so that under normal operating condi tions a substantial current is obtained for energizing the secondary circuit s, which current is uninfluenced by movement of the vehicle carried inductor over such magnetic masses on the roadbed as rails, derails, crossings and switch frogs, and so that under a tripping influence the cur rent for the secondary circuit s is reduced to an actual zero value, and so that furthermore for resetting the relay R a current may be generated for the secondary circuit 8 having a magnitude substantially greater than the normal energizing cu rent for this secondary circuit.

In exercising the desired control upon the sec-- ondary circuit 8 in producing the various operating currents therefor, I have found that phase changes as well as magnitude changes of mag netic flux produced by the cooperation of the vehicle carried and roadside inductors play a very important role; and accordingly the inductive apparatus embodying my present invention is designed and constructed so that the phase of the fluxes as well as the magnitude of the fluxes may be definitely predetermined for each of the operatons desired to be produced. This I accomplish first by providing a plurality of coils or windings for the secondary inductor such as W and W W so associated that the E. M. F.s developed therein are in opposite directions, with the construct on such that the magnitude and phases of these generated or developed E. M. F33 may be controlle to produce the intended results. To obtain the opposing E. M. F.s, the coil W of the secondary inductor is placed in the shunt flux path SFP, while the two coils W and W are placed in the or external flux paths EFP and the coils are interconnected so that the E. M. F.s generated in the coils W and W are in opposition to the E. M. F. generated in the coil W due to the rate change of flux in the two flux paths.

Now to obtain an exact neutralization of the sinusoidally varying E. M. F. in the secondary coil W against another sinusoidally varying E. M. F. in the secondary co ls W W it is essential that the developed E. M. F.s be made equal in magnitude and in phase. As is known, the E. M. F. generated in any coil is due to the flux variation through it, the magnitude of the E. M. F. developed depending upon the rate change of the flux and the phase of the E. M. F. depend ng upon the phase of the flux variation. For example, two E. M. F.s due to magnetic fluxes varying in the same Way and in equal amounts maybe out of phase if the maximum value of the flux causing one is 90 out of phase with the maximum value of the flux causing the other. It follows from this that in order to exactly balance the coils of the secondary S, the flux components in the external and shunt magnetic paths must be made equal in magnitude and must be either in phase or 180 outof phase.

These considerations I apply in constructing the vehicle and roadside inductive apparatus by attacking and operating on each component of the magnetic flux separately. For predetermining the magnitude of the magnetic fluxes in th external and shunt paths, I select suitable dimensions of the main core 10 and the shunt core 12 and suitable relative values of the windngs in the coils W to W as will be pointed out more particularly hereinafter; and to obtain a fixed value of flux magnitude, I preferably make the shunt core 12 adjustable to and from the main core 10, leaving an adjustable air space x therebetween, as clearly shown in Fig. 2 of the drawings. To predetermine and operate upon the phases of the fluxes in the external and shunt magnetic paths, I first make the same magnetomotive force operate upon the shunt secondary 3i sentia in order to balance or equalize the phases o such phases to be balanced, not only t arrange the opposing secondary coils across the same magnetizin potential, but it is necessary or highly desirable to equalize or balance the loss components in both the external and shunt magnetic paths.

This separation and control of the phasean magnitude components of the flux may now be more clearly by consderin the vector diagrams forming part Fig. 2 of the drawings, four vector diagrams being shown for correspondingly different roadside conditions.

The vector diagram A depicts the operating characterist cs of the secondary S of the vehicle carried inductor under normal train running conditions. ma tude of the fluxes in the shunt and external 1 he are so preadjusted as to produce a ma nitude of E. M. F. for the top coil W designa d 91 and for the bottom coils WW a magnitude desgnated as 83.- The arrangement or the coil W and the opposing coils W W to be fed by the same magnetizing potential of the primary P and the equalization of the losses in the shunt and external flux paths produces the substantially 180 out of phase relation between said E. M. Ffs in the oppos ing coils, with the result, as shown vectorially, that a resultant E. M. F. or" 8 is produced for energizing the secondary circuit 3. In practice, as will be described more in detail hereinbelow, the losses in the exte and shunt paths are equalor neutralized for the tripping condition or operation so that under normal running conditions the fluxes in two paths are sl ghtly shifted from 189 out of phase, but this shift is insuflicient, (being of the order of 1) to disturb the resultant E. M. F. produced.

Now under a tripping oper tion, as when the vehicle inductor VI is over an inert mass M, the magnitudes of the fluxes are changed in such a way as to produce equal and exactly opposing M. for the opposin coils of secondary, as is illustrated by the vector diagram B, a slight decrease of the M. the top coil W to 99 being produced, and an increase of'E. M. F. in the lower coil W and W to 90 being produced, with the result that resultant E. M. F. is exactly zero. The introduction of the magnetic mass M in the external flux path has the effect of changing the loss component in the external flux path, b at due to the efiicient construction and hence the small eddy current and hysteresis losses of the roadside inductor, v5- shift in phase will be but about 1, producing the balanced fluxes both in magnitude and in phase, as shown by the vector B.

will be shown below, the equalization of the loss components is effected by balancing the losses in the shunt and external flux paths, as well as by efiiciently organizing the inductors to produce extremely low losses for both magnetic circuits.

Due to this organization and cooperation of parts, I am enabled not only to produce a substantial resultant E. M. F. for the normal energizing current of the secondary S, but to reduce such E. M. F. to an actual zero value when a tripping or deenergizing operation of the secondary circuit is to be effected. I am enabled, moreover, by means of this construction to cause the vehicle carried inductor to differentiate in its operation of the relay R between the inert magnetic mass M and other inert magnetic masses on the roadbed such as rails, crossings, switch frogs and the like, so that the tripping operation can only be produced by a tripping inductor of the desired characteristics. This I illustrate in the vector diagram C of Fig. 2, showing that no tripping operation is produced over an iron rail. When the vehicle inductor VI moves over a magnetic mass such as an iron rail or the like, the losses produced by such magnetic mass due to the nonlaminated structure thereof have the effect of changing or shifting the phase of the flux in the external flux path EFL and hence shifting the phase of the E. M. F. developed in the coils W and W located in this path. Therefore although the magnitude change in the flux produced by such other magnetic bodies may be the same as forthe inert trip element as indicated by a comparison of the vector diagrams B and C, the phase shift which may approximate 6 produces a resultant E. M. F. in the secondary circuit 8 equal, as indicated, to about 10, which is substantially the same as the resultant produced under normal running conditions, as shown in the vector diagram A. Hence it will now be understood that the movement of the vehicle carried inductor over rails and the like will produce the same resultant action on the secondary circuit 3 as is produced therein under normal running con'ditons, and that therefore the vehicle carried apparatusis in no way disturbed by movemnt over rails, switch frogs and the like.

The action of the roadside inductor RI in tuned circuit is depicted in vector diagram D, from which it will be seen that the tuned circuit in effect introduces a very high loss component in the external flux path shifting the external flux about 21 from the flux in the shunt flux path, this re sulting in a corresponding shift of the E. M. F. developed in the opposing secondary coils W and W It will be noted that movement of the vehicle inductor over the tuned roadside inductor produces the same drop in the magnitude of the E. M. F. in the upper coil as is produced under the tripping operation, while the increase in the magnitude of the E. M. F. in the opposing coils W and W is not so great as that produced by the inert track element. However, the phase shift produces a resultant E. M. F. in the secondary circuit s equal to 32, which will be noted to be about four times the value of the normal energizing E. M. F. of said circuit.

To make effective these operations or influences where a single relay R is employed, the said relay may be provided with a contact 13 normally closed for maintaining energized the vehicle carried apparatus, which contact is opened under a tripping operation, and a second contact 14 normally open but which may be closed to assume the dotted line position shown in Fig. 2 of the drawings when a second and larger than the normal energizing current is developed in the secondary circuit 3.

By means of this construction, therefore, it will be seen that the phases of the fluxes, as well as the magnitudes thereof if desired, are definitely controlled-to produce well-defined actuating influences in the vehicle carried inductor which range from the value of zero to a value of 32 in zones which are separated by wide margins of safety one from the other.

While in the apparatus shown in Fig. 2 I operate both upon the magnitude as well as the phases of the flux variations, it will be understood that apparatus may be designed in which the phases alone are made controlling while the magnitudes of the flux may remain invariant or even be made unequal. Thus in an apparatus such as is shown in Fig. 2, the normal resultant may be produced by fluxes equal in magnitude but shifted in phase with suflicient losses introduced by the tripping element to shift the fluxes to positions exactly opposite in phase, thus effecting the neutraliza tion. The magnitudes of the opposing E. M. F.s should be made equal, however, for the tripping operation where a single relay element R of the type shown in Fig. 2 is employed. Where, however, other types of relays are used such as a relay of the two-element type, the magnitudes of the opposing E. M. F.s may be made unequal, and this I illustrate with the apparatus shown in Fig. 3 of the drawings.

In the apparatus shown in Fig. 3 of the drawings, I show a two-element relay R having the elements 15 and 16, the element 15 being connected in a secondary circuit 8' and the element 16 being connected in another secondary circuit 8 circuit 9 being fed by a coil W and secondary circuits s being fed by the two coils W and W both arranged in a manner similar to that described in connection with Fig. 2 across the same magnetizing potential of a primary P, which primary is in a primary circuit 11 connected to an alternating current source of energy A. C. The coils W and W W are arranged respectively in the shunt and external flux paths SFP and EFP respectively. Normally the elements of relay R may be actuated by currents shifted in phase (different from out of phase) to close a contact 13, which currents may be unequal and which may be shifted to 90 out of phase with each other, although unequal, to effect a no torque condition in the relay and hence an opening of the contact 13'. The phase in the currents may be also shifted (for purposes of resetting the apparatus) to a degree substantially larger than the normal out of phase relationship to close the second contact 14. To produce a 90 out of phase relation between the currents in the elements of the relay R to correspond to a 180 shift in phase in the magnetizing voltages, I show a condenser K in the secondary circuit s functioning to produce a current in phase with the voltage generated in coil W and I make the circuit 5 inductive so that the current therein is 90 out of phase with the voltage generated in coils W W Then when the generating voltages are 180 out of phase with each other, the energizing currents for the elements of the relay R are 90 out of phase with each other (no torque condition).

The results are illustrated by the three vector diagrams forming part of Fig. 3, the vector diagram A showing the unequal magnetizing voltages for the opposing coils W and W W shifted, however, in phase to produce a resultant torque in the relay R, the vector diagram B showing the shifting of the voltages to positions exactly opposite in phase so as to produce a no torque condition in said relay R. The vector diagram C shows the condition of operation when the vehicle inductor moves over a tuned roadside inductor, under which condition a substantial shift in the phase or" the flux in the external flux path is produced to efiect the corresponding shift in phase in the energizing currents of the elements of the relay R.

Referring now to Fig. l of the drawings, I show the inductive apparatus of Fig. 2 applied for controlling a number of vehicle carried circuits to produce the normal tripping and resettin operations thereof. The circuits controlled by the relay R are energized by a direct current source of energy D. C. such for example as the eXciter for the field of the generator A. C., the contact 13 of the relay R controlling the normal circuit, thecontact l4 controlling the reset circuit, and a third contact 17 controlling a delay circuit for the relay 3,.

The normal energizing circuit controls the operation of a translating relay B and comprises the D. C. source of energy, conductors l8 and 19, contact 13 normally closed, conductor 20, a manually operable switch 21, conductors 22 and 23 of the relay R conductors 24 and 25, stick contact 26 of relay R and conductors 2T, 28 and 29 back to the direct current source D. C. When the relay R is tripped, opening the contact 13, this circuit is opened and will be maintained open until reset at the stick contact 26.

The resetting circuit for the translating relay R comprises the source of energy D. C., conductors 18 and 19, the trip contact 13, conductor 20, switch 21, conductors 22 and 23, relay element R conductors 24 and 30, contact 14 closed when a resetting impulse is obtained and con ductors 31 and 29 back to the direct current source D. C. The resetting impulse is of short duration, taking place only upon cooperation of the vehicle carried and roadside inductors, and hence the contact 14 is closed for a brief period only. However, the energizing of the relay R by the resetting circuit picks up the contact 26, and since the trip contact 13 is closed, the normal circuit is reset.

For the purpose of delaying the release of the reset contact 14 to carry the apparatus over transients and the like, the additional contact 17 is provided for controlling a delay circuit comprising the energy source D. C., conductors 18 and 19, a conductor 32, a holding magnet 33 for contacts 13, 1e and 17, conductor 35, a contact 36 of a thermostat switch release mechanism 37, conductor 38, contact 1'? of relay R closed, and conductors 39, 31 and 29 back to the energy source D. C. The thermostat release 3? is con structed so that when the same is heated, after a predetermined interval the contact 36 thereof is opened to break this delay circuit. While the delay circuit is closed, however, it maintains the energiaation of the magnet 33 and hence maintains closed the contacts thereof.

The relay B may control other vehicle carried circuits such as are described in the copending application of Shaver & Meisel, Ser. No. 138,369, filed Oct. 1. 1926 for Train control system.

In Figs. 4 to 8 of the drawings, I show the constructional details of both the vehicle carried and roadside inductors. The core 10 on which the primary coil P and the two secondary coils W 2 and W are mounted is composed of laminated sheets,

as clearly shown in Fig. '6 of the drawings, and this core together with the pole pieces 10a and 101; are supported in the bottom wall 40 of an inductor casing generally designated as 41 by means of bolts 42, 42, the poles 10a and 10b beingpreferably extended laterally by being made fan,- shaped with insulating pieces i3, 43 arranged between the laminated extensions. The shunt 12 carrying the shunt winding W and proded with the pole extensions 12c and 12b 'is alefl made of laminated sheets, as clearly shown in Figs. 5 and 5 of the drawings, and this shunt core is fixed to a pair of brackets i4, 44 supported in turn by adjusting bolts 45, 45 on the top wall 46 of the inductor casing, this adjustment being provided for varying the air gap .12, a: between the shunt and main cores for the purpose, as hereinbeiore described, oi predetermining the magnie tude of the flux in the shunt path. This adjustment is held fixed by means of the set, screws 47, l? anchored in the inductor casing 46 and bearing on opposite sides of the shunt core bracket 44, 44.

The inductor casing or housing 41 is made of a non-magnetic casting known as Nomag, which material is composed of pig iron containing a percentage of manganese and nickel with some aluminum, said material having excellent electrical characteristics from the standpoint of being nonmagnetic and having high resistance, both of which are highly desirablein order to reduce to a minimum the losses in the casing. The casing contains a front cover 43 which is insulated from the remaining part of the casing by a rubber gasket 49. This cover may however be made of an insulating material. The splitting up of the closed metal circuits in the casing reduces the eddy current losses, and for the purpose of permitting a close approximation of the physical air gap to an actual magnetic air gap, I employ a pair of windows 50, 58 of thin tough non-magnetic metals such as nichrome having a very high specific electrical resistance. The vehicle inductor casing is supported by a bracket 51 by means of the bolts 52, 52, which bracket may be vertically adjusted on the supporting casting 53 afiixed to a suitable part of the vehicle.

For producing the flux distribution hereinbefore described, the windings W 2 and W both have the same number of turns, while the winding W has approximately four times the number of turns of either W or W With the differences in core dimensions illustrated, this gives approximately equal flux densities in the shunt and main core ends and results in substantially perfect neutralization of the voltages in the secondary when the inductor is over an inert track element. The final adjustment ismade by varying the position of the shunt core so as to reduce to zero the current in the secondary circuit s'when the locomotive inductor is placed directly over a roadside inductor with the coil W open and with an air gap M and 10 of four inches.

The roadside inert mass M with the extension poles parts of the main core 10, the core M being made of laminated sheets, as clearly shown in Fig. 8 of the drawings, about which core is wound the roadside coil W, and the extension poles 11a and 1172 are also made fan-shaped as well as wedgeshaped with insulated laminations, as clearly shown in Fig. 7 of the drawings. The roadside inductor casing 54 is also provided with the nichrome windows 55, and said casing is made of a plurality of parts insulated from each other as at la and 11b is constructed similarly to the 56, 57 and 58 to produce the splitting up of the closed metal circuits. The material for the roadside inductor casing is also preferably Noniag metal for the purpose hereinabove referred to. The roadside inductor may be of a length somewhat larger than the over-all length of the vehicle carried inductor as illustrated in Fig. 4 of the drawings. The said roadside inductor may also be provided with anchoring portions 59, 59 for affixing the same to the ties or other part of the roadbed.

By means of this construction, the vehicle carried and roadside inductors are made very efficient and the losses both of the magnetic circuits or flux paths reduced to a minimum, the losses in said paths being, moreover, equalized. After having reduced the eddy current and hysteresis losses to the greatest engineering minimum, I find it desirable, where there is a lack of complete balance in the losses in the shunt and external magnetic paths, to supplement the eddy current losses in the shunt circuit by an amount equal to the difference between the losses in the shunt circuit and the losses in the external circuit. This I prefer to do by arranging another winding 60 (see Fig. 4) which is closed on itself and which is wound around the shunt circuit, in which closed Winding eddy currents may be introduced. This winding may be either a single turn of a suitably small size copper Wire or else may be several'turns of copper wire with an external resistor which may be made adjustable to empirically balance the losses in the two magnetic circuits. The reason why I prefer this method of equally phasing the magnetic flux is as follows. It is desirable, as pointed out above, to make the engine inductor responsive in the most widely different degrees to the inert track elements and to other iron masses in the vicinity of the engine inductor, so that discriminating influences may be produced. If the exterior magnetic circuit were designed to have a relatively high loss and the shunt circuit compensated accordingly, then there would be a smaller difference between the operation of the inert track element and the operation due to occasional masses of iron nearby, such masses of iron having a relatively high loss due to their nonlaminated structure, as was stated heretofore. It is therefore desirable to construct the roadside inductor with extremely low losses, and to then equalize the losses by compensating the shunt circuit. It also happens that this solution is economical of power because the higher eflicient external magnetic circuit requires much less power to generate the required magnetic flux than one of higher loss characteristics. The roadside inductor parts may be suitably attached to the inductor casing 54 as by means of the securing bolts 61, 61 anchored to the bottom wall of the casing or housing 54.

The construction and operation of the train control system embodying the inductor apparatus of my present invention and the many advantages thereof will in the main be fully apparent from the above detailed description of the underlying principles thereof and the application of the inductive apparatus to the control of vehicle carried circuits. In addition to the functions and results hereinbefore enumerated, it will be evident that with the use of the inductive apparaus of the present invention, inert roadside apparatus and roadside circuits devoid of any energy source may be employed or utilized for producing a positive deenergizing or tripping operation of vehicle carried circuits and a positive reenergizing or resetting operation of such circuits, the construction being, moreover, such that the normal operation of the vehicle carried apparatus may be maintained under normal or clear roadside conditions. It will be further manifest that these functions are accomplished with the use of a single roadside inductor and a single vehicle carried inductor. t will be further seen that all of the sequential functions necessary for operating a train control system may be effected by means of a single relay either of the type shown in Fig. 2 or of the two-element type shown in Fig. 3. The ability of the vehicle inductor to discriminate between an inductor mass and other masses on the roadbed, such as rails and the like, is another highly important advantage of the inductive combination. It will also be manifest that the circuits provided are all of the normally closed circuit type, a break in the circuits producing a tripping operation of the vehicle carried apparatus. The shorting of parts such as the condensers c or c in Fig. 2 of the drawings will also produce a deenergizing operation, since either corresponding circuit would be detuned. It may be explained that the detuning of the trackside circuit t has the same effect as the introduction of the magnetic mass M into the external flux path, this producing a tripping operation. Other important advantages will be apparent to those versed in the art of automatic train control.

While I have shown and described my invention in the preferred form, it will be apparent that many changes and modifications may be made in the structure disclosed without departing from the spirit of the invention, defined in the following claims.

I claim:

1. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, roadside apparatus including an inductor comprising a metallic mass under certain roadside conditions and operative for influencing the vehicle carried inductor for producing therein a flux change differing in phase from that produced by the influence of other metallic masses on the roadbed, such as rails, crossings and the like, and means for causing said vehicle carried inductor to discriminate in its operation of said electrically operated device between the flux phase changes produced by the influence of said roadside inductor and the influence of said other metallic masses.

2. In an induction train control system, vehicle carried apparatus including an inductor, roadside apparatus including an inductor comprising a metallic mass under certain roadside conditions and operative for influencing the vehicle carried inductor for producing therein a flux change differing in phase from that produced by the influence of other similarly or differently shaped metallic masses on the roadbed, such as rails, crossings and the like, and means for causing said vehicle carried inductor to discriminate in its operation of the vehicle carried apparatus between the flux phase changes produced by the influence of said roadside inductor and the influence of said other metallic masses.

3. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, roadside apparatus including an inductor comprising a metallic mass under certain roadside conditions and operative for influencing the vehicle carried inductor for producing therein a magnitude change of flux substantially the same as and a phase change of flux substantially diflerent from the magnitude and phase changes of flux produced by the influence of other similarly shaped metallic masses on the roadbed, such as rails, crossings and the like, and means for causing said vehicle carried inductor to descriminate in its operation of said electrically operated device between the flux phase changes produced by the influence of said roadside inductor and the influence of said other metallic masses.

i. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor embodying inductively coupled coils for controlling the oper-' ation of said-device, roadside apparatus including an inductor arranged to influence the vehicle carried inductor and comprising a metallic mass under certain roadside conditions, and means for causing said vehicle carried inductor to discriminate in its operation of said electrically operated element between an influence of said roadside inductor when acting as a metallic mass and the influence of other metallic masses on the roadbed such as rails, crossings, switch frogs and the like, the said other metallic masses operating to produce a phase difference between the fluxes in said coupled coils different than that produced by the inductor mass, and the said means functioning to discriminate between said different flux phase diflerences.

5. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, said inductor embodying a primary winding, an A. C. source therefor, a plurality of secondary windings coupled to the primary winding and arranged in a plurality of magnetic paths, the fluxes of which are normally less than 180 out of phase with each other but which can be set 180 out of phase with each other, and a roadside inductor for influencing the vehicle carried inductor to produce the 180 out of phase relationship of said fluxes.

6. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, said inductor embodying a plurality of windings arranged in a plurality of magnetic paths, the fluxes of which are normally less than 180 out of phase with each other but which can be set 180 out of phase with each other; and a roadside inductor for influencing the vehicle carried inductor to produce the 180 out of phase relation of said fluxes.

7. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, a vehicle carried alternating current source for said inductor, said inductor embodying a plurality of windings arranged in a plurality of magnetic paths; and a roadside inductor for influencing the vehicle carried inductor to change the phase relationship between the fluxes of said magnetic paths and produce a 180 out of phase relationship therebetween.

8. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the-operation of said device, said inductor embodying a plurality of windings arranged in a plurality of magnetic paths; and a roadside inductor for selectively influencing the vehicle car-' ried inductor to change the flux conditions of one magnetic path relative to the other for selectively producing fluxes 180 out of phase with each other and fluxes less than 180 out of phase with each other.

9. In an induction train control system, vehicle carried apparatus comprising an electrically operated device and an inductor for controllingthe operation of said device, said inductor embodying a plurality of windings arranged so that the E. M. F.s developed in said windings diifer from but may be set 180 out of phase with each other, and means for influencing said inductor to substantially produce the 180 out of phase relationship between E. M; F.s.

10. In an induction train control system, vehicle carried apparatus comprising an electrically operated device and an inductor for controlling the operation of said device, said inductor embodying a plurality of secondary windings receiving energy from a single energy source and arranged so that the E. M. F.s developed in said windings are normally less than 186 out of phase with each other but may be set 180 out of phase with each other, and means for influencing said inductor .to sub stantially produce the 180 out of phase relationship between said E. M. F.s.

11. In an induction train control system, vehicle carried apparatus including an electrically operated device, an inductor embodying a plurality of windings associated so that alternating current E. M, Ffs developed in said windings are in opposition and have a resultant magnitude suflicient to energize the said device; and a road-v side inductor for influencing said vehicle inductor, said windings being symmetrically arranged electrically with respect to an energy source so that when influenced by the roadside inductor the magnitude of said resultant E. M. F. is reduced to zero. 1

12. In an induction train control system, vehicle carried apparatus including an electrically operated device, an inductor embodying a plurality oi-secondary windings connected so that E. M. Ffs developed in said windings are in opposition and have a resultant magnitude sufiicient to energize said device; and a roadside inductor for influencing said vehicle inductor to produce E. M. F.s in said windings 180 degrees opposite in phase. 1

13. In an induction train control system, vehicle carried apparatus including an electrically operated device, an inductor embodying a plurality of windings associated so that E. M. F.s developed said windings are in opposition and have a resultant magnitude suflicient to energize said device; and a roadside inductor for influencing said vehicle inductor to produce E. M. F.s in said windings equal in magnitude and 180 degrees opposite in phase. I

14. In an induction train control system, ve-

hicle carried apparatus including anelectrically operated device, an inductor controlling said device and embodying a plurality of secondary windings connected so that E. M. Ffs developed in said windings are in opposition and have a given resultant magnitude, and a roadside inductor selectively operable for influencing said vehicle inductor to either decrease said resultant magnitude to zero or to substantially increase the same.

15. In-an induction train controlsystem, vehicle carried apparatus including an electrically operated device, an inductor for controlling said device and embodying a plurality of windings comiected so that E. M. F.s developed in said windings are in opposition and have a given resultant magnitude suiiicient to energize said device; and a roadside inductor for influencing said vehicle inductor to either produce E. M. F.s exactly opposite in phase for deenergizing said device or to produce E. M. F.s differing in phase for producing a different resultant magnitude to reenergize said device to a new position.

16. In an induction train control system, vehicle carried apparatus including an inductor embodying a plurality of windings connected so that E. M. F.s developed in said windings are in opposition and have a given resultant magnitude; and a roadside inductor for influencing said vehicle inductor to either produce E. M. F.s exactly opposite in phase for reducing said resultant to zero or to produce E. M. F35 differing in phase for producing a different resultant magnitude.

17. In an induction train control system, vehicle carried apparatus including a controlled device, an inductor embodying a fluctuating source of energy and a plurality of windings fed from said source of energy and connected so that E. M. F.s developed in said windings are in opposition and have a resultant magnitude sufficient to energize said device; and a roadside inductor selectively operable for influencing said vehicle inductor to either decrease said resultant magnitude to zero or to substantially increase the same.

18. In combination, a controlled circuit and an inductor mechanism for controlling the operation of saidcircuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces.

19. In combination, a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces, said magnetic paths having equalized low loss components.

20. In combination, a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces, the resultant of which is effective for normally energizing said controlled circuit.

21. In combination, a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external flux path and a shunt flux path and a secondary inductor having windings arranged in both of said flux paths, said windings being connected to produce opposing electromotive forces, the said flux paths and windings being predetermined to produce E. M. F.s in said windings 180 out of phase with each other when a magnetic mass is introduced in said external magnetic path.

22. In combination, a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external fiux path and a shunt flux path and a secondary inductor having windings arranged in both of said flux paths, said windings being connected to produce opposing electromotive forces having normally a given resultant magnitude, said flux paths being predetermined to produce E. M. F.s in said windings equal in magnitude and opposite in phase when a magnetic mass is introduced in said external flux path.

23. In combination, a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary energized inductor having an external magnetic path and a shunt magnetic path and a secondary energy receiving inductor having at least two windings, one arranged in each of said magnetic paths, said windings being connected to produce opposing electromotive forces.

24. In combination, a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary energizinginductor having an external magnetic path and a shunt magnetic path and a secondary energy receiving inductor having at least two windings, one arranged in each of said magnetic paths, said windings being connected to produce opposing electromotive forces, said magnetic paths having equalized low loss components.

25. In combination, vehicle carried apparatus including an inductor mechanism comprising a primary inductor having an'external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces; and a roadside inductor cooperating with said vehicle inductor mechanism and arranged to be included in said external magnetic path, said vehicle carried inductor mechanism and roadside inductor including means for producing equal loss components in said external and shunt magnetic pathsa 26. In combination, vehicle carried apparatus including an inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces; and a roadside inductor cooperating with said vehicle inductor mechanism and arranged to be included in said external magnetic path, said magnetic paths being predetermined or adjusted to produce E. M. F.s in said windings equal in magnitude and opposite in phase when the vehicle inductor mechanism moves over the roadside inductor.

27. In combination, vehicle carried apparatus including an inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces; and a roadside inductor cooperating with said vehicle inductor mechanism and arranged to be included in said external magnetic path, said vehicle carried inductor mechanism and roadside inductor including means for producing equal loss components in said external and shunt magnetic paths, said magnetic paths being adjusted to produce E. M. F.s in said windings equal in magnitude and opposite in phase when the vehicle inductor mechanism moves over. a roadside inductor.

28. In combination, an inductor mechanism comprising a primary inductor, a fluctuating current source therefor, a secondary inductor having at least two windings each inductivelycoupled to said primary inductor and connected in circuit to produce E. M. F.s in opposite directions, the said secondary windings being symmetrically disposed with respect to the primary inductor and being each arranged across the same magnetomotive potential of the primary inductor.

29. In combination, an inductor mechanism comprising a primary inductor, a fluctuating current source therefor, a secondary inductor having at least two windings each inductively coupled to said primary inductor and connected in circuit to produce opposing E. M. F.s having a given resultant magnitude, the said secondary windings being symmetrically disposed with respect to the primary inductor and being each arranged across the same magnetomotive force of the primary inductor.

30. In combination, an inductor mechanism comprising a primary inductor, a fluctuating current source therefor, a secondary inductor having at least two windings each inductively coupled to said primary inductor in different flux paths and connected in circuit to produce E. M. F.s in opposite directions, the said secondary windings being symmetrically disposed with respect to the primary inductor and being each arranged across the same magnetomotive potential of the primary inductor.

31. In combination, an inductor mechanism comprising a primary inductor, a fluctuating current therefor, and a secondary inductor coupled to the primary inductor having three windings, one arranged in one magnetic path and the other two arranged in a second magnetic path, both magnetic paths beginning at the poles of the primary inductor. I

32. In an induction train control system, a vehicle carried apparatus including a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces having a resultant magnitude sufficient to normally energize the said controlled circuit; and a roadside inductor mechanism for influencing the vehicle carried inductor mechanism for relatively changing the fluxes in said external and shunt magnetic paths for modifying the resultant electromotive force in said secondary inductor.

33. In an induction train control system, a vehicle carried apparatus including a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces having a resultant magnitude sufiicient to normally energize the said controlled circuit; and a roadside inductor mechanism for influencing the vehicle carried inductor vehicle carried apparatus including a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor 1.

mechanism'comprising a primary inductor having an external magnetic path and a shunt mag: netic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to. produce opposing electromotive forces having a resultant magnitude sufficient to normally energize the said controlled circuit; and'a roadside inductor mechanism for influencing the vehicle carried inductor mechanism for reducing the resultant electromotive force in said secondary inductor substantially to zero.

35. In an induction train control system, a vehicle carried apparatus including a controlled circuit and an inductor mechanism for controlling the operation. of said circuit, said inductor mechanism comprising a primary inductorhaving an extenal magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic. paths, said windings being connected to produce opposing electromotive forces and having a resultant magnitude sufficient to normally energize the said controlled circuit; and a roadside inductor mechanism for influencing the vehicle carried an extenal magnetic path and a shunt magnetic Y path and a secondary inductor having windings arranged in both of said magnetic paths; said windings being connected. to produce opposing electromotive forces having aresultant magnitude sufiicient to normally energize the said con-.-

trolled circuit; and a roadside inductor mechanism comprising a metallic mass for influencing the vehicle carried inductor mechanism for changing the relative fluxes in said external and shunt magnetic paths for producing in said windings neutralizing electromotive, forces to deenergizethe controlled circuit. 7 r

37. In an induction train control system, a vehicle carried apparatus including a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths,

said windings being connected to produce electromotive forces opposite in phase and having a resultant magnitude sufiicient to normally energize the said controlledcircuit; and a roadside inductor mechanism for influencingthe vehicle I J carried inductor mechanism for changing the relative fluxes in said external and shunt magnetic paths to equalize the magnitudes without changing the phases of the electromotive forces developed in said secondary windings.

38. In an induction train control system, a. vehicle carried-apparatus including a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path of equalized low losses and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces and having a resultant magnitude sufficient to normally energize the said controlled circuit; and a roadside inductor mechanism for influencing the vehicle carried inductor mechanism for changing the relative fluxes in said external and shunt magnetic paths for modifying the resultant electromotive force in said secondary inductor.

- 39. In an induction train control system, a vehicle carried apparatus including a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths, said windings being connected to produce opposing electromotive forces having a resultant magnitude sufficient to normally energize the said controlled circuit; and a roadside inductor mechanism selectively operable for influencing the vehicle carried inductor mechanism for changing the fluxes in said external and shunt magnetic paths for selectively decreasing or increasing in magnitude the resultant electromotive force in said secondary inductor.

40. In an induction train control system, a vehicle carried apparatus including a controlled 1 circuit and an inductor mechanism for controlphases of the fluxes in said external and shunt magnetic paths for increasing in magnitude the resultant electromotive force in said secondary inductor.

41. In an induction train control system, a vehicle carried apparatus including a controlled circuit and an inductor mechanism for controlling the operation of said circuit, said inductor mechanism comprising a primary inductor having an external magnetic path and a shunt magnetic path and a secondary inductor having windings arranged in both of said magnetic paths,

said windings being connected to produce opposing electromotive forces having a resultant magnitude surficient to normally energize the said controlled circuit; and a roadside inductor mechanism embodying a tuned circuit devoid of an energy source for influencing the vehicle carried inductor mechanism for changing the phase of the flux in said external path relative to said shunt magnetic paths for increasing in magnitude the resultant electromotive force in said secondary inductor.

42. In an induction train control system, vehicle carried apparatus comprising a controlled device, a vehicle carried inductor mechanism including a primary inductor and a secondary inductor, said secondary inductor having a winding linked in a local magnetic. path with said primary inductor and having another winding linked in an external magnetic path with said primary inductor, said secondary windings being connected to said device for controlling the same, and a roadside inductor cooperating with said vehicle carried inductor and arranged to form part of and be threaded by said external magnetic path for predeterminedly changing the relation between said local and external magnetic paths.

43. In an induction train control system, vehicle carried apparatus comprising a controlled device, a vehicle carried inductor mechanism including a primary inductor, an A. C. source therefor, and a secondary inductor, said secondary inductor having a winding linked in a local magnetic path with said primary inductor and having another winding linked in an external magnetic path with said primary inductor, said secondary windings being-connected across similar magnetomotive potentials of said primary and being connected to said device for controlling the same, and a roadside inductor cooperating with said vehicle carried inductor and arranged to form part of and be threaded by said external magnetic path for predeterminedly changing the relation between said local and external magnetic paths.

44. In an induction train control system, vehicle carried apparatus comprising a controlled device, a vehicle carried inductor mechanism including a primary inductor and a secondary inductor, said secondary inductor having a winding linked in a local magnetic path with said primary inductor and having another winding linked in an external magnetic path with said primary inductor, said secondary windings being connected to said device for controlling the same, and a roadside inductor cooperating with said vehicle carried inductor and arranged to form part of and be threaded by said external magnetic path for predeterminedly changing the relation between said local and external magnetic paths, said roadside inductor including a core, a circuit having a winding on said core, and means for open and close circuiting said circuit.

45. In an induction train control system, vehicle carried apparatus comprising a controlled device, a vehicle carried inductor mechanism including a primary inductor and a secondary inductor, said secondary inductor having a winding linked in a local magnetic path with said primary inductor and having another winding linked in an external magnetic path with said primary inductor, said secondary windings being connected to said device for controlling the same,

and a roadside inductor cooperating with said vehicle carried inductor and arranged to form part of and be threaded by said external magnetic path for predeterminedly changing the relation between said local and external magnetic paths, said roadside inductor including a tuned circuit.

46. In an induction train control system, vehicle carried apparatus comprising a controlled device, a vehicle carried inductor mechanism including a primary inductor and a secondary inductor, said secondary inductor having a winding linked in a local, magnetic path with said primary inductor and having another winding linked in an external magnetic path with said primary inductor, said secondary windings being connected to said device for controlling the same,

vand a roadside inductor cooperating with said vehicle carried inductor and arranged to .form part of and be threaded by said external magnetic path for predeterminedly changing the relation between said local and external magnetic paths, said local and external magnetic paths being arranged to have equalized loss components.

47. In an induction train control system, vehicle carried apparatus comprising a controlled device, a vehicle carried inductor mechanism including a primary inductor and a secondary inductor, said secondary inductor having a winding linked in a local magnetic path with said primary inductor and having another winding linked in an external magnetic path with said primary inductor, said local magnetic path having a fixed loss component and having a flux which is substantially invariant during operation of the inductor, said secondary windings being connected to said device for controlling the same, and a roadside inductor cooperating with said vehicle carried inductor and arranged to form part of and be threaded by said external magnetic path for predeterminedly changing the relation between said local and external magnetic paths.

&8. In an induction train control system, vehicle carried apparatus comprising a controlled device, a vehicle carried inductor mechanism including a primary inductor and a secondary inductor, said secondary inductor having a winding linked in a local magnetic path with said primary inductor and having another winding linked in an external magnetic path with said primary inductor, said secondary windings being connected to said device for controlling the same, and a roadside inductor cooperating with said vehicle carried inductor and arranged to form part of and be threaded by said external magnetic path for predeterminedly changing the relation between said local and external magnetic paths, the said local magnetic path having a flux magnitude which is substantially invariant during operation.

49. In an introduction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, said inductor embodying a plurality of windings arranged in a plurality of magnetic paths, and a roadside inductor for selectively influencing the vehicle carried inductor to change the flux conditions of one magnetic path relatively to the other for selectively effecting a given phase difference in the fluxes of said paths to produce a tripping operation of said device and a different phase difference of the fluxes to produce a resetting operation of said device.

50. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, said inductor embodying a primary winding and a plurality of secondary windings arranged in a plurality of magnetic paths, and a roadside inductor including a roadside controlled winding for selectively influencing the vehicle carried inductor to change the iiux conditions of one magnetic path relatively to the other for selectively effecting a given phase difference in the fluxes of said paths to produce a tripping operation of said device and a different phase difference of the fluxes to produce a resetting operation of said device.

51. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, said inductor embodying windings arranged in two magneticpaths, a roadside inductor cooperable with said vehicle carried inductor so as to be embraced in one of said magnetic paths, and means whereby the loss components in both of said magnetic paths are equalized during a given cooperation between the vehicle carried and roadside inductors.

52. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, said inductor embodying windings arranged in two magnetic paths, a roadside inductor cooperable with said vehicle carried inductor, and means whereby the loss components in both of said magnetic paths are equalized during cooperation between the vehicle carried and roadside inductors.

53. In an induction train control system, vehicle carried apparatus including an electrically operated device and an inductor for controlling the operation of said device, said inductor embodying primary and secondary windings arranged in two magnetic paths, and a roadside inductor cooperable with said vehicle carried inductor, and means whereby the loss components and the magnetizing components in both of said magnetic paths are equalized during a given cooperation between the vehicle carried and roadside inductors.

Sd. In an induction train control system, a vehicle carried inductor mechanism comprising a core, a primary Winding on said core, a secondary winding on said core, said core having pole pieces arranged to cooperate with a roadside inductor, a second core associated with said first mentioned core, a secondary winding on said second core, and means for adjusting the loss component in the flux path between said cores.

55. In an induction train control system, a vehicle carried inductor mechanism comprising a 120 core, a primary winding on said core, a secondary winding on said core, said core having pole pieces arranged to cooperate with a roadside inductor,

a second core having poles spaced from poles of the first mentioned core, a secondary winding 125 only on said second core, and means for adjusting the one core relatively to the other to vary the magnitude of the flux linking the same.

56. In an induction train control system, a vehicle carried inductor mechanism comprising a 130 core, a primary winding on said core, a secondary winding on said core, said core having pole pieces arranged to cooperate with a roadside inductor,

a second core associated with said first mentioned core, a secondary winding on said second 135 core, both secondary windings being arranged across the same magnetomotive potential of the primary winding, and means for adjusting the loss component in the flux path between said cores.

57. In the inductor mechanism of claim 56, means for adjusting one core relatively to the other to fix the magnitude of the flux threading the same. 

